A multicomponent plastic in which at least one component is arranged in a manner distributed in spherical form in the volume of the remaining components and is enclosed by a dimensionally stable sheath or capsule is described in German Patent Application No. DE 10 2004 044 603.2. However, the multicomponent plastic used therein is not used as a plastic housing composition, but rather as an underfill material in the region of surface-mountable external contacts and in the form of solder balls which are intended to be applied to a customized circuit board. The curing agent of the two-component plastic for the underfill material is accommodated in capsules, the sheath of which has a thermoplastic which is intended to release the curing agent only when at least the solder temperature for soldering the surface-mountable external contacts onto the customized circuit board has been attained.
The use of such a two-component plastic having a curing agent enclosed in a thermoplastic sheath as a plastic housing composition has the disadvantage that at least the softening temperature of the thermoplastic of the capsule has to be reached for release of the curing agent.
For a plastic housing composition, there is the disadvantage that, after the emergence of the curing agent at the softening temperature of the capsules and the curing of the plastic housing composition to form a plastic housing, the plastic housing composition is then hot and, consequently, the plastic housing has to be cooled to room temperature. Due to the high coefficient of thermal expansion, the plastic housing shrinks and brings about warping, for example, of a circuit substrate on which a semiconductor chip is mounted. Such warping can render the semiconductor housings that are to be formed unusable if the warping exceeds permissible tolerances. In particular, if a plurality of semiconductor houses are intended to be formed simultaneously on a panel, the extreme shrinkage of a plastic housing composition preheated in this manner is problematic for further processing, in particular singulation to form individual housings of the panel due to the incipient warping.
Therefore, there is a need to create a plastic housing composition which exhibits a reduction of a shrinkage effect and hence of warping of semiconductor devices.